Megafauna Extinction

If you have visited the Heritage Center in Bismarck you were undoubtedly impressed by the mastodon skeleton on display. At the end of the Pleistocene or ice age, what is now North Dakota was home so some very large mammals. This megafauna included mastodon, mammoth, giant ground sloth, and others.

We know many of these species went extinct around 9-12,000 years ago. What we don’t know is why. Various causes have been proposed including climate and vegetation change, hunting by humans, or perhaps an extraterrestrial impact, such as that of a comet or asteroid.

Thanks to a recent study by Jacquelyn Gill from the University of Wisconsin, Madison and her colleagues, we may be closer to determining the cause of these extinctions. Their study was recently published in the prestigious journal Science.

Sediments at the bottom of a lake may provide a record of the areas ecological history. So Gill and her colleagues dated and analyzed the sediments at the bottom of a lake in Indiana for pollen, plant fragments, and other biological material to determine past climate and vegetation. What was particularly interesting about their study is that they also analyzed the sediments for the spores of a fungus that lives in the dung of large herbivores. Lots of spores mean lots of animals and their dung and visa versa. What an interesting approach!
They discovered that the megafauna decline and extinction started about 14,800 years ago. This is before the major change in vegetation and earlier than the hypothesized extraterrestrial impact or extinction caused by humans hunting during what is called the Clovis Period. The authors do, however, suggest that hunting by pre-Clovis humans may have been a factor. This new information may help direct future research to determine the actual cause the extinctions.

Regardless of the academics of this extinction, visit the Heritage Center and view the mastodon on display. It represents an interesting period in our history, and one that is becoming better understood.

I would like to extend a belated Merry Christmas to all of you. And here is wishing you and yours a joyous Holiday Season.

Chuck Lura

Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Dakota College at Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.